<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<script src="js/jquery-3.7.0.min.js"></script>
	<script>
		function big(){
			var size =  $("p").css("font-size")
			size = size.replace("px","")
			$("p").css("font-size",++size + "px")
		}
		
	</script>
	<body>
		<h1>jquery使用步骤</h1>
		<p>1.引入jquery</p>
		<p>2.选择节点</p>
		<p>3.api操作节点</p>
		<input type="button" value="+" id="" onclick="big()">
	</body>
</html>